AMapUI.loadUI(['overlay/SimpleControl'], function(SimpleControl) {
    
    var controlBar = document.getElementById('control-bar');
    var zoomInBtn = document.getElementById('zoom-in');
    var zoomOutBtn = document.getElementById('zoom-out');
    var centerMapBtn = document.getElementById('center-map');

    zoomInBtn.addEventListener('click', function() {
        map.setZoom(map.getZoom() + 1);
    });

    zoomOutBtn.addEventListener('click', function() {
        map.setZoom(map.getZoom() - 1);
    });

    centerMapBtn.addEventListener('click', function() {
        map.setCenter([116.39,39.9]);
    });

});